Many electronic devices available to a user nowadays provide geo-location and routing information. Some of these electronic devices are dedicated purely to provision of the geo-location and routing information. An example of such devices would be a portable GPS navigator, such as those available from TomTom Corporation of Amsterdam, The Netherlands. Another example of such devices would be a GPS navigator, built-in into a car. For example, many car manufacturers provide an option to include a built-in navigation system into their cars. Other electronic devices provide geo-location and route information as an add-on to other functions. For example, most smartphones available on the market today include an application that provides geo-location and routing services.
In order to provide such geo-location and routing information services, a typical electronic device includes a satellite navigation module, for example, one based on a global positioning system (GPS). The GPS allows a satellite navigation receiver, e.g., a GPS receiver module of a smartphone, to determine its location and velocity based on satellite signals. The GPS may include a constellation of GPS satellites orbiting the Earth. There can be at least four GPS satellites visible at a given time and a given place on the Earth's surface. Each GPS satellite continuously broadcasts GPS signals at a predetermined frequency. The GPS signals contain time and orbital information for the satellites. A GPS receiver can receive the GPS signals transmitted from at least four GPS satellites synchronously. Based on the time and orbital information from at least four GPS satellites, geographical coordinates of the GPS receiver including latitude, longitude, and altitude can be calculated.
It is generally known that the accuracy of the GPS-based positioning system depends, largely, on atmospheric characteristics, as well as the location of the electronic device that attempts to use the GPS-based positioning system. For example, if the user of the electronic device attempts to use the GPS-based positioning system in an underground parking, the user will generally experience problems with using GPS-based positioning system.